The story
According to the Oxford English Dictionary, sense 2 (“state of disgrace, exclusion from a group, or punishment”) is attested earlier than sense 1 (“place where a child is sent to sit as a punishment”), though logically sense 2 follows from sense 1. The term was popularized by the professional nanny and author Jo Frost (born 1970) in the British television show Supernanny (first broadcast in 2004).
Etymology from Wiktionary, CC BY-SA 4.0.